The present invention relates to an engine mounting configuration, and more particularly to an engine mounting configuration for mounting a turbofan gas turbine engine to an aircraft pylon.
A gas turbine engine may be mounted at various points on an aircraft such as a pylon integrated with an aircraft structure. An engine mounting configuration ensures the transmission of loads between the engine and the aircraft structure. The loads typically include the weight of the engine, its thrust, aerodynamic loads, maneuver loads, and rotary torque about the engine axis. The engine mounting configuration must also absorb the deformations to which the engine is subjected during different flight phases and the dimensional variations due to thermal expansion and retraction.
One conventional engine mounting configuration includes a pylon having a forward mount and an aft mount. The front mount handles the thrust load from the engine as well as vertical and side loads from the front of the engine. The rear mount handles vertical and side loads from the rear of the engine and the engine torque.
Although effective, one disadvantage of this mounting arrangement is the relatively large “punch loads” into the engine cases from the thrust links which react the thrust from the engine and couple the thrust to the pylon. These loads tend to distort the intermediate case, low pressure compressor (LPC), fan, and high pressure compressor (HPC) cases. The distortion can cause the clearances between the static cases and rotating blade tips to increase. This may negatively affect engine performance and increase fuel burn.
Furthermore, when reacting thrust at the front mount, the engine centerline is deflected downward therefrom. The engine centerline may be still further deflected downward from the nacelle air load when the aircraft rotates while taking off. To accommodate this centerline deflection, the engine compressor and turbine blade require larger tip clearances which may negatively affect engine performance.
Accordingly, it is desirable to provide an engine mounting configuration which minimizes backbone bending and engine case distortion.